Expose Frame::detach() to the Blink API layer.

public/web/WebFrame.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 100 matching lines @@
     // Returns the number of live WebFrame objects, used for leak checking.
     BLINK_EXPORT static int instanceCount();
 
     virtual bool isWebLocalFrame() const = 0;
     virtual WebLocalFrame* toWebLocalFrame() = 0;
     virtual bool isWebRemoteFrame() const = 0;
     virtual WebRemoteFrame* toWebRemoteFrame() = 0;
 
     BLINK_EXPORT bool swap(WebFrame*);
 
-    // This method closes and deletes the WebFrame.
+    // This method closes and deletes the WebFrame. This is typically called by
+    // the embedder in response to a frame detached callback to the WebFrame
+    // client.
     virtual void close() = 0;
 
+    // Called by the embedder when it needs to detach the subtree rooted at this
+    // frame.
+    void detach();
 
     // Basic properties ---------------------------------------------------
 
     // The unique name of this frame.
     virtual WebString uniqueName() const = 0;
 
     // The name of this frame. If no name is given, empty string is returned.
     virtual WebString assignedName() const = 0;
 
     // Sets the name of this frame. For child frames (frames that are not a
@@ skipping 542 matching lines @@
     WebPrivateOwnPtr<OpenedFrameTracker> m_openedFrameTracker;
 };
 
 #if BLINK_IMPLEMENTATION
 Frame* toCoreFrame(const WebFrame*);
 #endif
 
 } // namespace blink
 
 #endif